During treatment of diabetic ketoacidosis, which electrolyte disturbance is most important to monitor to prevent complications from insulin therapy?

• A. Potassium
• B. Sodium
• C. Magnesium
• D. Calcium

Answer: (A)

Potassium is the electrolyte you monitor most closely during insulin therapy in diabetic ketoacidosis. Giving insulin and correcting acidosis drives potassium from outside cells into the cells, which can cause a rapid drop in serum potassium. Even though patients with DKA often have total body potassium depletion from diuresis, the serum level can be normal or high at first. If you don’t watch and replace potassium, this rapid shift can lead to significant hypokalemia and dangerous arrhythmias. So, potassium levels are checked frequently and replacement is guided by a safe range, typically holding or delaying insulin if potassium is too low and starting insulin with concurrent potassium replacement if it’s in a safer range.